A Study of the Fully Differential Inclusive Semileptonic B Meson Decay Rate

Author: Lipeles, Elliot

Year: 2004

Degree: Dissertation (Ph.D.)

Advisor: Weinstein, Alan Jay

Committee Members: Weinstein, Alan Jay; Filippone, Bradley W.; Porter, Frank C.; Wise, Mark B.

Option: Physics

DOI: 10.7907/W3Q5-5B34

Abstract

We present a study of the fully differential inclusive semileptonic B meson decay rate. Using a maximum likelihood fit, we extract the fractional contributions from the B → Xclv processes with Xc = D, D*, D**, and nonresonant Xc, and the process B → Xulv. From the fit results, we extract moments of B → Xclυ̅ differential decay rate and the partial branching fraction of the B → Xulυ̅ decay in a restricted region of phase space. The region in which the B → Xulυ̅ partial branching fraction is measured is Mx < 1:5 GeV/ c2, q2 > 11 GeV2 / c4. This measurements is used to extract CKM parameter |Vub| = (4:73±0:23±0:82±0:18±0:56±0:66) x 10-3, where the uncertainties are due to statistics, detector systematics, B → Xclv model dependence, B → Xulυ̅ model dependence, and theoretical uncertainties. From the 〈 M2x - M̅2D〉moment, the first moment of the photon energy spectrum in B → Xsγ, and the semileptonic B branching fraction, we extract the CKM parameter |Vcb| = (4:12 ± .10 ± 0.09 ± 0.16) x 10-2, where the uncertainties are due to the measurement of the semileptonic B decay rate, the moments measurements, and theoretical uncertainties. Both CKM parameter extractions use Heavy Quark Eective Theory (HQET) predictions for inclusive semileptonic B decay. The measured moments are also used to test related predictions.

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